diff --git a/R/app.R b/R/app.R
index 0561a2e..57ae69a 100644
--- a/R/app.R
+++ b/R/app.R
@@ -1,8 +1,9 @@
 #' Run the application server.
 #'
+#' @param host The hostname to serve the application on.
 #' @param port The port to serve the application on.
 #'
 #' @export
-run_app <- function(port = 3464) {
-    runApp(shinyApp(ui, server), port = port)
+run_app <- function(host = "127.0.0.1", port = 3464) {
+    runApp(shinyApp(ui, server), host = host, port = port)
 }
diff --git a/man/run_app.Rd b/man/run_app.Rd
index c408207..3de7878 100644
--- a/man/run_app.Rd
+++ b/man/run_app.Rd
@@ -4,9 +4,11 @@
 \alias{run_app}
 \title{Run the application server.}
 \usage{
-run_app(port = 3464)
+run_app(host = "127.0.0.1", port = 3464)
 }
 \arguments{
+\item{host}{The hostname to serve the application on.}
+
 \item{port}{The port to serve the application on.}
 }
 \description{